Method and device for the scattering of drones on curved paths around one or more reference points

Abstract

The disclosure relates to the deployment and maintenance of a belt of autonomous sensors fitted out with warning sensors to monitor the area surrounding one or more sensitive points. It relates especially to anti-missile and anti-aircraft warning systems for naval surface ships against missiles and aircraft flying at low and very low altitudes. It consists in controlling the paths of the drones solely by means of their radius of curvature for which they receive an instructed value from the reference point or points. This instructed value is encoded by a frequency of a radioelectric signal sensitive to the Doppler effect. A modification of this instructed value of radius of curvature as a function of the signal of a proximity sensor makes it possible to avoid all problems of collision and to keep the drones at equal distance from one another. This mode of control proves to be particularly efficient and, at the same time, very simple.

What is claimed is: 
     
       1. A method for controlling flight paths of a plurality of drones, each of said plurality of drones being in flight about at least one radio-control transmitter and each comprising a transmitter and a receiver, said method comprising the steps of: transmitting a control signal from respective of the at least one radio-control transmitter, each control signal being transmitted at a different frequency corresponding to the at least one radio-control transmitter from which the control signal was transmitted, each control signal having a frequency which corresponds to an instructive value of radius of curvature to be generally followed by at least a subset of said, drones and which increases and decreases with said instructed value of radius of curvature;   receiving each control signal with said receiver in respective of said drones;   detecting at respective of said drones instructive values of radius of curvature corresponding to the different apparent frequencies of the control signals;   weighting at each of said drones the instructive values of radius of curvature and forming a weighted instruction value of radius of curvature; and   actuating a rudder unit in respective of said drones so as to guide respective of said drones along respective paths corresponding to said weighted instruction value of radius of curvature that was formed in each of said drones in said weighting step.   
     
     
       2. The method of claim 1, further comprising the steps of: detecting at each of said drones whether a relative distance from one of said drones is closer than a predetermined distance to another of said drones; and   modifying said weighted instruction value so as to increase said relative distance if in said detecting step said another of said drones is closer than said predetermined distance.   
     
     
       3. The method of claim 1, further comprising the steps of: detecting at each of said drones whether a relative distance from one of said drones is further than a predetermined distance to another of said drones; and   modifying said weighted instruction value so as to decrease said relative distance if in said detecting step said another of said drones is detected as being farther than said predetermined distance.   
     
     
       4. The method of claim 1, further comprising the steps of: detecting at each of said drones whether a relative distance at which one of said drones is being followed by another of said drones is closer than a predetermined distance; and   reducing said radius of curvature of said path for said one of said drones that detects in said detecting step that said another drone is following closer than by said predetermined distance.   
     
     
       5. The method of claim 1, further comprising the steps of: detecting at each of said drones whether a relative distance at which one of said drones is being followed by another of said drones is greater than a predetermined distance; and   increasing said radius of curvature of said path for said one of said drones that detects in said detecting step that said another drone is following by greater than said predetermined distance.   
     
     
       6. A drone flight control system, comprising: at least one radio-control transmitter, each radio-control transmitter comprising a radio frequency transmitter being located at a respective reference point and each being configured to transmit a control signal having a frequency which corresponds to an instructed value of radius of curvature to be generally followed by at least a subset of said drones, which increases and decreases with said instructed value of radius of curvature and which is different than for other control signals; and   a plurality of airborne drones arranged in respective flight paths about said at least one radio-control transmitter, each of said plurality of drones comprising,   a receiver configured to receive each control signal at the different frequencies,   a detection circuit configured to determine apparent frequencies of the different frequencies of the control signals and determine corresponding instructive values of radius of curvature, said instructive values of radius of curvature each corresponding to a radius of curvature for a flight path followed by said drone,   a weighting circuit configured to weigh, the instructive values of radius of curvature and form a weighted instruction value of radius of curvature, and   a rudder unit configured to guide said drone along said flight path in accordance with said weighted instruction value of radius of curvature.   
     
     
       7. The system of claim 6, wherein each of said plurality of drones further comprises a proximity sensor that senses positions of at least another one of the plurality of drones and produces a modified weighted instruction value in response to said at least another one of the plurality of airborne drones being in a predetermined range. 
     
     
       8. The system of claim 7, wherein said proximity sensor is configured to detect when a distance from another one of the plurality of airborne drones is less than a predetermined distance and respond by changing said modified weighted instruction value so that said rudder unit changes an angular speed of the drone unit and causes said drone to move away from said another drone unit. 
     
     
       9. The system of claim 7, wherein said proximity sensor is configured to detect when a distance from another one of the plurality of drones is greater than a predetermined distance and respond by changing said modified weighted instruction value so that said rudder unit changes an angular speed of the drone so as to move closer to said another drone. 
     
     
       10. The system of claim 7, wherein said weighting circuit comprises a fuzzy logic circuit.